Magnetic bearing for active centering of a body movable relative to a static body with respect to at least one axis

摘要

A magnetic bearing secures active magnetic centering with respect to at least one centering axis of a body movable relative to another a static body. It comprises, on each side of a plane of symmetry perpendicular to the centering axis and containing a reference axis: at least one permanent magnet magnetized parallel to the reference axis, at least one combination comprising a coil wound on a ferromagnetic core disposed to procure a magnetic flux parallel to the reference axis and ferromagnetic members adapted to provide a closed magnetic path for magnetic flux produced by the magnet and the coil via airgaps on the centering axis separating the movable body from the body body. A control circuit comprises a sensor responsive to relative movement between the movable body and the body body along the centering axis and adapted to feed to the coil a current adapted to correct any such relative movement. Two ferromagnetic plates carried by the body body have the magnet and the core clamped between them. A ferromagnetic polepiece carried by the movable body provides a closed magnetic path via the previously mentioned airgaps for the magnetic flux circulating in these ferromagnetic plates.